1. Field of the Invention
The present invention relates to a library retrieving and repositing robot that performs, in succession, the tasks of quickly retrieving individual books desired by library patrons from among many books arranged on the bookshelves of the library, and transporting them; and taking books that have been returned by library patrons, and returning them to the bookshelves one at a time, securely placing each book upright in its proper shelf location. It also relates to an automatic library system incorporating such a robot in a configuration that is fully compatible with existing the open-shelf-type book racks most commonly used in libraries today.
2. Description of the Related Art
Recent years have seen an increased awareness of the need for lifelong learning, and major growth in knowledge-based industries. Along with this, the general public has come to make greater use of existing general library facilities, and to expect a higher level of service from them. Consequently, librarians and other skilled library workers are now expected to provide many highly specialized services that require detailed knowledge of publications and library science. In the majority of the libraries in existence today, however, a large part of the normal workday of such skilled library staff members is taken up with handling library books: i.e., finding a book desired by a library patron, taking it off the shelf, and placing it in the hands of the user who requested it; and taking books that have been returned by users, carrying them to the bookracks, and returning them to their proper locations on the shelves. To improve the availability of specialized intellectual services that can only be rendered by skilled library staff demands that mechanization be employed to streamline the task of retrieving and repositing library books requested by library patrons.
Known in the art are book storage management systems that use xe2x80x98automated stock storage technologyxe2x80x99 such as disclosed, for example, in Japanese Laid-open patent publication no. H07-81706 [(See also U.S. Pat. No. 5,690,463)] which describes a mechanized system for improving the efficiency of tasks involved in selecting desired books and withdrawing them from a book storage facility designed for extremely low-cost storage of the large book stocks maintained by libraries. Such book storage management systems, however, operate only in conjunction with specially-designed book storage facilities. They will not work with the ordinary libraries in existence today, where members of the general public frequently roam through the bookracks, picking out desired books directly, and taking them off the shelves. These prior book storage management systems are not compatible with the manual selection and removal of a desired book on the spot: Their storage areas serve simply as warehouses in which books are placed for storage.
In these conventional book storage management systems, the many books to be stored are classified in advance, and then divided for placement, by class, in a large number of containers, each of which is analogous to one section of a large book rack. To provide the most economical book storage, these many containers are then stacked one on top of the other in a stack room, to form high, closely-spaced stacks that enable as many books as possible to be stored in the smallest possible space. A large-scale conveyer system links the stack room to book users. When a library patron requests a desired book, a mechanical apparatus finds the container that contains the class of books to which the desired book is assigned. The selected container with its many books is then placed on the conveyer that carries it to a library user area, where the desired book within the class contained in that container can easily be found, and removed by hand.
To implement this large conveyer system in a common library would require costly and inconvenient construction work to remodel the existing facility. This is a major problem. Also, once the system has been installed, the conveyer placement is not something that can easily be changed. This places severe constraints on changes in the layout and configuration of the book stacks. Another problem is that in this system, there is simply no way that general library patrons could be allowed to walk freely among the stacks, removing books from the containers and replacing them by hand. Users who are accustomed to doing this in libraries in which the books are kept in open bookshelves would undoubtedly feel alienated by a book storage management system such as that described above. A library adopting such a system would also necessarily assume a major workload in terms of safety management and system maintenance, and adopting such a system would therefore not provide the needed gains in library staff efficiency through mechanization of the detailed book retrieval and repositing work performed by the staff.
For the foregoing reasons, there is a need for an automated library book retrieving and repositing system that can be implemented in common libraries in existence today without major remodeling of facilities, and that can also be employed in libraries in which bookracks are subject to rearrangement in a variety of configurations.
The present invention was conceived with the above problems and the needs of existing libraries in mind. It is an object of the present invention to provide a library book management system incorporating a robot that can perform, in lieu of library staff, the tasks of locating and removing individual books, and later replacing the books, when users are finished with them, by gently reshelving individual books in their proper locations on the bookshelves. Implementing such an automated robotic library book retrieval and repositing system in conventional libraries will improve efficiency by greatly reducing the book retrieval and repositing workload of library staff, thus enhancing the level of specialized intellectual services that can be provided by those libraries. It is a further object of the present invention to reduce damage to books during robotic book removal and reshelving operations.
To solve the above problems, the present invention provides a book retrieving and repositing robot. The robot has a carriage that moves itself around the periphery of a bookrack in which are formed a plurality of shelf sections. Mounted on the carriage are a hand mechanism; a controller for controlling three-dimensional motion of the hand mechanism; and a computer for determining both the book identification information for a requested book and the requested book""s prescribed shelf section storage location information, and controlling the motion of the carriage and the hand mechanism based on that information. The robot""s hand mechanism includes an identification information recognition unit for detecting shelf section identification information indicated on the bookrack, as well as book identification information indicated on the library books stored in each section, and recognizing a requested book""s prescribed shelf section storage location, and a requested book present at that prescribed shelf section storage location; a book pullout mechanism for pulling-out a requested book from a row of books in a shelf section; and a book-holding mechanism for grasping the pulled-out book and removing it from the bookrack. The invention is constituted such that a desired book can be retrieved from the bookracks without bothering the library staff.
Also provided is a book retrieving and repositing robot having a carriage as described above, on which are mounted a hand mechanism; a controller for controlling the three-dimensional motion of the hand mechanism; and a computer for determining a returned book""s prescribed shelf section storage location information and controlling the motion of the carriage and the hand mechanism based on instructions received from a book checkout/return counter. The hand mechanism of the robot includes an identification information recognition unit for detecting shelf section identification information indicated on the bookrack, as well as book identification information indicated on the library books stored in the various sections, and for recognizing a returned book""s prescribed shelf section storage location, and the end of a row of books stored in that section; and a book-holding mechanism for grasping the returned book, aligning it with the end of the row of books in the prescribed shelf section storage location, and pushing it in. The invention is constituted such that a returned book can be reshelved in a library""s bookracks without bothering the library staff.
In addition, the above problem can be solved through a series of automated book retrieval and repositing systems through which a desired book can be caused to be removed from the bookrack by instructions issued from a checkout/return counter, without bothering the library staff. To achieve this, book retrieving and repositing robots like the one described above are placed in a bookrack area in which the bookracks are arranged such that library staff and patrons may directly access and manually remove books from the racks at will. At a book checkout/return counter, book identification information for a book requested by a library patron is input to a host computer, which then searches for the requested book""s prescribed shelf section storage location information, and outputs, along with the requested book identification information, the requested book""s prescribed shelf section storage location information. A mobile computer mounted on the book retrieving and repositing robot then controls the motion of the carriage and the hand mechanism of a book retrieving and repositing robot, based on the requested book identification information and the requested book""s prescribed shelf section storage location information output from the host computer, to retrieve the desired book from the bookrack.
Also, a series of automated book retrieval and repositing systems can be realized for repositing a book returned to the library in its proper location in the bookrack by issuing instructions from a checkout/return counter, without bothering the library staff. To accomplish this, a book retrieving and repositing robot as described above is placed in a bookrack area such as that described above. At a book checkout/return counter, book identification information for a book returned by a library patron is input to a host computer. That computer is then caused to search for the returned book""s prescribed shelf section storage location information, and to output the returned book""s prescribed shelf section storage location information. A mobile computer mounted on the book retrieving and repositing robot controls the motion of the carriage and hand mechanism of the book retrieving and repositing robot, based on the returned book""s prescribed shelf section storage location information output from the host computer, to return the desired book to its proper location in the bookrack.
The present invention is also configured so as to prevent damage to books during their removal from, and reshelving in a bookrack. For book removal, a hand mechanism of the book retrieving and repositing robot of the present invention has a finger lever, on the forward end of which is provided a book retracting finger for making frictional contact with, and/or hooking, the upper edge of a book, for pressing the book downward and pulling it out in order to remove it from a bookshelf. To avoid damaging the book during this process, the force applied to the finger lever to press the upper edge of the book downward is a resilient force. To avoid damaging returned books when they are being reposited in a row of books in a bookrack by a book retrieving and repositing robot, a special bookend is placed in each shelf section of the bookrack for facilitating the gentle reshelving of books. To accomplish this, the bookend is configured such that, inside of a substantially wedge-shaped housing having trapezoid-shaped top and bottom surfaces and an inclined side surface, positioned at the wide end of the wedge-shaped housing, is a fixed guide roller, axially supported by a vertical shaft such that a portion of the outer circumference of the fixed guide roller partially protrudes outward of the housing through a window formed in the inclined side surface thereof Positioned at the narrow end of the wedge-shaped housing is a rocker arm having at a free end thereof a rocking guide roller axially supported by a vertical shaft, the other end of the rocker arm being axially supported by a vertical shaft such as to be rotatable thereabout in a manner such as to allow the rocking guide roller to float outward of a window formed in the inclined side of the housing. The bookends are provided on the bookshelf sections such as to be urged in the direction in which the rocking guide roller emerges from the window, with the wide end of the bookend facing the back of the bookshelf section and the inclined side of the bookend facing the end of a row of books on the bookshelf section, such that the wedge-shaped slot thus formed between the inclined side surface of the bookend and the end of the row of books can function as a guide slot for the reshelving of returned books.